An electric vehicle torque distribution method, system, electronic device and storage medium

Abstract

The application provides an electric vehicle torque distribution method, comprising S1, S2, S3 and S4. S1 sets a vehicle speed threshold value, a wheel speed change rate threshold value and a vehicle slip rate threshold value according to a vehicle; S2 collects vehicle driving data, and calculates an actual wheel speed change rate and an actual vehicle slip rate according to the vehicle driving data; S3 compares the calculated actual wheel speed change rate, the actual vehicle slip rate, the wheel speed change rate threshold value and the vehicle slip rate threshold value, and obtains a vehicle driving condition; and S4 distributes torque occupancy rates of front wheels and rear wheels of the vehicle according to the driving condition and the actual vehicle slip rate. The electric vehicle torque distribution method can realize the calculation of the slip rate and the distribution of the torque output based on the calculation, so as to realize the rapid escape of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobiles, in particular to an electric vehicle torque distribution method, system, electronic device and storage medium. BACKGROUND

[0002] With the development of new energy vehicle technology, the new energy vehicle market has experienced explosive growth. Electric four-wheel drive is more rapid and precise than traditional four-wheel drive control, and has achieved good market satisfaction. At the same time, due to the rapid response of the motor, higher requirements are also put forward for the control system. For example, when the system detects slipping during escape and low adhesion high throttle starting, the TCS sends a torque reduction demand at this time. During this conversion process, it is easy to have a sense of impact. The general escape distribution logic is to calculate the slip ratio based on the difference between the wheel speed and the reference vehicle speed, and then distribute the front and rear axle torque according to the slip ratio.

[0003] However, in the underlying software, the wheel speed calculation speed is much lower than the motor speed calculation speed. For example, the transmission ratio of the motor and the wheel is 10, which means that the motor speed calculation module obtains 10 times the number of PWM signals of the wheel speed calculation module in the same time. The effective motor speed signal can be sent out quickly, and the effective wheel speed signal will be delayed for a period of time, such as Figure 1 is the comparison of motor speed and vehicle speed when a certain vehicle starts. The vehicle speed is delayed for a long time compared with the motor speed. As a result, a large slip occurs before the slipping escape condition is determined, the escape is delayed, and problems such as poor vehicle NVH effect and low adhesion starting jerk are caused.

[0004] The prior art (CN111731109A) discloses a vehicle torque distribution method, but does not analyze and calculate the vehicle slip ratio and the speed change rate, and does not consider the combination of the vehicle slip ratio and the torque distribution, resulting in that the torque distribution cannot be normally distributed under the condition of slipping, and a poor driving experience is caused. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an electric vehicle torque distribution method for identifying slipping on low adhesion road surface for electric four-wheel drive new energy vehicles, and controlling torque output and four-wheel drive distribution on this basis to realize rapid escape.

[0006] The present application provides an electric vehicle torque distribution method, comprising:

[0007] S1: setting a vehicle speed threshold, a wheel speed change rate threshold and a vehicle slip rate threshold according to the vehicle;

[0008] S2: collecting vehicle driving data, and calculating an actual wheel speed change rate and an actual vehicle slip rate according to the vehicle driving data;

[0009] S3: comparing the calculated vehicle actual slip rate, the wheel speed change rate threshold and the vehicle slip rate threshold to obtain a vehicle driving condition;

[0010] S4: distributing the torque occupancy rate of the front wheels and the rear wheels of the vehicle according to the driving condition and the vehicle actual slip rate.

[0011] In an embodiment of the present application, the vehicle speed threshold is in the range of 6-10 km / h, which is related to the vehicle speed when the vehicle starts with full throttle on a low adhesion road and appears to be jerky; the wheel speed change rate threshold is determined according to the maximum wheel speed change rate of the vehicle in a non-slip state, and the vehicle slip rate threshold is determined according to the maximum vehicle slip rate of the vehicle in a non-slip state.

[0012] In an embodiment of the present application, in the S2, the vehicle driving data includes a vehicle displacement speed and a wheel rotation speed, the vehicle displacement speed is obtained by a speedometer arranged at the bottom of the vehicle, and the wheel rotation speed is calculated by the rotation speed of the corresponding vehicle motor of the vehicle and the wheel radius of the corresponding wheel.

[0013] In an embodiment of the present application, in the S2, the wheel rotation speed is calculated in the following manner: wheel rotation speed = vehicle motor rotation speed * wheel radius * 0.377 / ratio, wherein ratio is the transmission ratio of the corresponding motor of the vehicle to the corresponding wheel.

[0014] In an embodiment of the present application, in the S2, the front wheel displacement slip rate, the front wheel speed slip rate, the rear wheel displacement slip rate and the rear wheel speed slip rate are obtained according to the vehicle displacement speed and the wheel rotation speed, the maximum value between the front wheel displacement slip rate and the front wheel speed slip rate is taken as the front wheel slip rate, and the maximum value between the rear wheel displacement slip rate and the rear wheel speed slip rate is taken as the rear wheel slip rate.

[0015] In an embodiment of the present application, in the S2, the wheel rotation speed includes a front wheel speed and a rear wheel speed, wherein the vehicle displacement speed is taken as a first reference vehicle speed, the smaller value between the front wheel speed and the rear wheel speed is taken as a second reference vehicle speed, the front wheel speed is the average value of the front left wheel speed and the front right wheel speed of the vehicle, and the rear wheel speed is the average value of the rear left wheel speed and the rear right wheel speed of the vehicle.

[0016] In one embodiment of the present application, the front wheel displacement slip ratio = | first reference vehicle speed - front wheel speed | / front wheel speed, the front wheel rotation slip ratio = | second reference vehicle speed - front wheel speed | / front wheel speed, the rear wheel displacement slip ratio = | first reference vehicle speed - rear wheel speed | / rear wheel speed, and the rear wheel rotation slip ratio = | second reference vehicle speed - rear wheel speed | / rear wheel speed.

[0017] In one embodiment of the present application, in the S2, the vehicle actual slip ratio comprises the front wheel slip ratio and the rear wheel slip ratio, and the rotation speed change rate is obtained by calculating the change rate of the wheel rotation speed per unit time.

[0018] In one embodiment of the present application, in the S3, when the vehicle speed of the vehicle is less than the vehicle speed threshold value, it is a starting vehicle condition; when the actual rotation speed change rate of the vehicle wheel is greater than the vehicle wheel rotation speed change rate threshold value, it is a slipping vehicle condition; and when the vehicle actual slip ratio is greater than the vehicle slip ratio threshold value, it is a slipping vehicle condition.

[0019] In one embodiment of the present application, in the S4, the torque is distributed according to the slipping conditions of the front wheel and the rear wheel of the vehicle; when the front wheel is in the slipping vehicle condition, the torque is distributed to the rear axle of the vehicle according to the size of the front wheel slip ratio; and when the rear wheel is in the slipping vehicle condition, the torque is distributed to the front axle of the vehicle according to the size of the rear wheel slip ratio.

[0020] The present application also provides an electric vehicle torque distribution system, comprising:

[0021] The acquisition module acquires vehicle driving data, wherein the vehicle driving data comprises vehicle displacement speed and wheel rotation speed.

[0022] The processing module processes the vehicle driving data to obtain front wheel slip ratio and rear wheel slip ratio.

[0023] The distribution module compares the front wheel slip ratio and the rear wheel slip ratio with a vehicle slip ratio threshold value to determine whether wheel slipping occurs, and distributes the torque occupancy proportion of the front wheel and the rear wheel according to the sizes of the front wheel slip ratio and the rear wheel slip ratio.

[0024] In one embodiment of the present application, the front wheel slip ratio in the processing module comprises front wheel displacement slip ratio and front wheel speed slip ratio, and the rear wheel slip ratio comprises rear wheel displacement slip ratio and rear wheel speed slip ratio; the maximum value of the front wheel displacement slip ratio and the front wheel speed slip ratio is taken as the front wheel slip ratio, and the maximum value of the rear wheel displacement slip ratio and the rear wheel speed slip ratio is taken as the rear wheel slip ratio.

[0025] In one embodiment of the present application, the vehicle slip rate threshold value is determined according to historical data collected by the collection module.

[0026] The present application also provides an electronic device comprising:

[0027] one or more processors;

[0028] a storage device storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement any of the above methods.

[0029] The present application also provides a computer-readable storage medium, characterized in that a computer program is stored thereon, which, when executed by a processor of a computer, causes the computer to perform any of the above methods.

[0030] The present application provides an electric vehicle torque distribution method, system, electronic device and storage medium, which can realize the calculation of vehicle slip rate and speed change rate.

[0031] Further, the torque distribution method of the present application judges the vehicle condition according to the calculated vehicle slip rate and speed change rate, and distributes the torque according to the slip rate.

[0032] The torque distribution method of the present application can quickly identify the slipping vehicle condition and intelligently distribute the torque proportion, so as to quickly help the slipping vehicle to get out of trouble. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 The flow chart of the method of the present application;

[0035] Figure 2 The flow chart of one embodiment of the present application;

[0036] Figure 3 The change chart of motor speed, wheel speed and motor output torque when the vehicle is running normally in one embodiment of the present application;

[0037] Figure 4 The change chart of motor speed, wheel speed and motor output torque when the vehicle is slipping in one embodiment of the present application.

[0038] Figure 5System architecture diagram of the system of the present application. DETAILED DESCRIPTION

[0039] The advantages and effects of the present application can be easily understood by those skilled in the art from the above description. The present application can also be implemented or applied in other different embodiments, and various modifications or changes can be made to the details in the specification based on different views and applications without departing from the spirit of the present application.

[0040] It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present application are for describing specific embodiments, and are not intended to limit the protection scope of the present application. The test methods in the following embodiments not specified in the specific conditions are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0041] Reference should be made to Figures 1 to 5 It should be noted that the structures, proportions, sizes, etc. shown in the drawings accompanying the specification are only used to illustrate the content disclosed in the specification, to enable those skilled in the art to understand and read, and are not intended to limit the conditions under which the present application can be implemented, and therefore do not have technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that can be achieved by the present application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the specification are only for the convenience of clear description, and are not intended to limit the scope in which the present application can be implemented, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope in which the present application can be implemented.

[0042] The present application provides an electric vehicle torque distribution method, which can realize the calculation of slip rate and the distribution of torque output based thereon to realize the rapid escape of the vehicle. Specifically, the electric vehicle torque distribution method of the present application comprises S1, S2, S3 and S4. S1 sets a vehicle speed threshold, a wheel speed change rate threshold and a vehicle slip rate threshold according to the vehicle; S2 collects vehicle running data, calculates the actual wheel speed change rate and the actual vehicle slip rate according to the rear wheel speed vehicle running data; S3 compares the calculated rear wheel speed actual wheel speed change rate, the rear wheel speed actual vehicle slip rate, the rear wheel speed wheel speed change rate threshold and the rear wheel speed vehicle slip rate threshold to obtain the vehicle running condition; and S4 distributes the torque occupancy rate of the front wheel and the rear wheel of the vehicle according to the rear wheel speed running condition and the actual vehicle slip rate.

[0043] As Figure 1As shown, the torque distribution method of the present case includes four steps, which are: S1 setting each threshold, S2 collecting driving data and calculating actual speed change rate and actual slip rate based on the driving data, S3 comparing actual speed change and actual slip rate with the threshold to obtain driving vehicle condition and distributing torque of front wheel and rear wheel according to driving vehicle condition and S4 actual slip rate.

[0044] As shown, first, it is ensured that the actual vehicle speed is less than the preset speed, and then the slip condition of the vehicle is determined, and the preset speed is set to 100 km / h in the present embodiment. After ensuring that the speed is less than the preset speed, the vehicle speed change rate, the wheel speed slip rate and the vehicle displacement slip rate are calculated. When the vehicle speed change rate or the vehicle displacement slip rate is greater than the preset value, it is determined that the vehicle is in the slip condition. At this time, the vehicle reduces the torque rising gradient, takes the maximum value of the wheel speed slip rate and the vehicle displacement slip rate as the actual slip rate of the vehicle, and determines the torque distribution coefficient according to the size of the actual slip rate of the vehicle. Figure 2

[0045] As shown, in step S1, three thresholds are first set, which are the speed threshold, the speed change rate threshold and the slip rate threshold. The speed threshold is generally 6-10 km / h, which is used to determine whether the vehicle is in the starting condition. When the vehicle speed is less than the speed threshold, the vehicle is determined to be in the starting condition. The speed threshold is determined according to the speed at which the vehicle has a jerk when starting at full throttle on a low adhesion road. The wheel speed change rate is the speed change amount of the vehicle per unit time, and the speed change rate threshold is generally determined according to the actual performance of the vehicle. Because the maximum acceleration of the vehicle does not change during normal driving, when the actual acceleration is greater than the maximum acceleration, it is likely that the speed change rate is caused by wheel slip. Therefore, when the actual speed change rate of the vehicle is greater than the speed change rate threshold of the vehicle, it is determined that the vehicle is slipping. The threshold of the speed change rate is generally determined according to the maximum change rate when the vehicle starts, and the speed change rate threshold must be greater than the maximum change rate when the vehicle starts, otherwise misjudgment is likely to occur. The wheel speed change rate is calculated based on the collected motor speed information, and is irrelevant to the actual displacement speed of the vehicle. The actual slip rate of the vehicle includes the front wheel slip rate and the rear wheel slip rate, and the calculation of the slip rate needs to be accurate to the front wheel slip rate and the rear wheel slip rate, which are used for torque distribution. When the front wheel slip rate is greater than the slip rate threshold, the front wheel is slipping; when the rear wheel slip rate is greater than the slip rate threshold, the rear wheel is slipping. The slip rate threshold is also obtained according to the actual performance of the vehicle, and is a constant that can be adjusted flexibly according to different vehicles. Figure 1 2

[0046] ​​​In step S2, the vehicle displacement speed and the wheel rotation speed are collected and calculated respectively. The vehicle displacement speed is collected from the speed acquisition device of the vehicle chassis, and the wheel rotation speed includes the front wheel speed and the rear wheel speed, which can be calculated based on the wheel radius and the wheel transmission ratio combined with the motor rotation speed. The calculation process is: front wheel speed = front wheel motor rotation speed * front wheel radius * 0.377 / ratio, rear wheel speed = rear wheel motor rotation speed * rear wheel radius * 0.377 / ratio, wherein ratio is the wheel transmission ratio. The front wheel speed is the average of the front left wheel speed and the front right wheel speed, and the rear wheel speed is the average of the rear left wheel speed and the rear right wheel speed.

[0047] Further, after obtaining the front wheel speed and the rear wheel speed, the front wheel rotation slip rate and the rear wheel rotation slip rate can be calculated in combination with the vehicle displacement speed, wherein the smaller value of the front wheel speed and the rear wheel speed is taken as the second reference vehicle speed, and the calculation process is: front wheel rotation slip rate = |second reference vehicle speed - front wheel speed| / front wheel speed; rear wheel rotation slip rate = |second reference vehicle speed - rear wheel speed| / rear wheel speed. At the same time, the front wheel displacement slip rate and the rear wheel displacement slip rate can be obtained by calculating the vehicle displacement speed, the front wheel speed and the rear wheel speed, wherein the vehicle displacement speed is taken as the first reference vehicle speed, and the calculation process is: front wheel displacement slip rate = |first reference vehicle speed - front wheel speed| / front wheel speed; rear wheel displacement slip rate = |first reference vehicle speed - rear wheel speed| / rear wheel speed. Among them, the maximum value of the front wheel displacement slip rate and the front wheel rotation slip rate is taken as the front wheel slip rate, and the maximum value of the rear wheel displacement slip rate and the rear wheel rotation slip rate is taken as the rear wheel slip rate. The actual wheel speed change rate is the change amount of the wheel rotation speed in unit time.

[0048] In step S3, the calculated actual wheel speed change rate, front wheel slip rate and rear wheel slip rate are compared with the speed change rate threshold and slip rate threshold in step S1, and it can be determined whether the vehicle is slipping. When it is determined that the vehicle is slipping, the vehicle opens the slip escape mode, and at the same time reduces the torque rising gradient. Reducing the torque rising gradient can reduce the increase amount of torque in the same time, and finally reduce the wheel end torque. After the TCS (traction control system or drive slip prevention system) intervenes, the wheel end torque is forced to be the torque issued by the TCS, and in this conversion process, torque jump is easy to occur, causing jerk, which needs to be reduced before the TCS torque reduction demand is issued to avoid sudden change and suppress jerk. Then, according to the front wheel slip rate and the rear wheel slip rate calculated in step S2, the torque is distributed. When it is determined that the front wheel is slipping, the torque is distributed to the rear axle according to the actual slip rate; when it is determined that the rear wheel is slipping, the torque is distributed to the front axle according to the actual slip rate. The specific distribution amount is intelligently adjusted according to the actual performance of different vehicles.

[0049] As Figure 3 ,4 As shown, from top to bottom are the vehicle displacement speed, wheel speed and torque variation diagrams of the vehicle. Figure 3 For the change trend of each value in the normal driving process of the vehicle, the wheel speed changes by 60 km / h within 0-2.5 s, the motor speed changes at a rate of about 800 rpm / s within 0-2.5 s, and the slip rate is less than 0.1 according to the vehicle wheel radius and the transmission ratio, so the torque distribution is stable at 380 after about 0.3 s. Figure 4 For the corresponding change trend diagram when the rear wheel slips, the motor speed changes at a rate of about 4000-8000 rpm / s (revolutions per second / second) at the beginning of the slip (about 0.3 s), and the slip rate is about 0.5 or more. The update speed of the motor speed is faster than the wheel speed, and the actual vehicle slip rate is calculated according to the logic of the application to determine the slip. As can be seen from the torque change trend, there is a large mutation in the torque after the TCS intervenes, and before that, the slip is identified in advance by the motor speed change rate, then the torque rising process is slowed down, and the sudden reduction of the torque caused by the TCS intervention is reduced or even eliminated, and the jerk is inhibited.

[0050] Further, by Figure 4 It can be clearly seen that the vehicle slips at about 0.25 s, and if the torque distribution method of the present application is not used, the torque will decrease sharply or remain unchanged, causing the vehicle to lose control, but at this time the torque slowly decreases and tends to be stable, and when the vehicle exits the slip condition and starts to accelerate, the torque returns to the initial distribution amount and remains stable.

[0051] As Figure 5 shown, the application also provides a power torque distribution and output system for an electric four-wheel drive vehicle, comprising a collection module, a processing module and a distribution module. The collection module collects vehicle driving data, and the vehicle driving data includes vehicle displacement speed and wheel rotation speed; the processing module processes the vehicle driving data to obtain front wheel slip rate and rear wheel slip rate; the distribution module compares the front wheel slip rate and the rear wheel slip rate with the vehicle slip rate threshold value to determine whether the wheel slips, and distributes the torque occupancy proportion of the front wheel and the rear wheel according to the size of the front wheel slip rate and the rear wheel slip rate.

[0052] Among them, the vehicle speed threshold value is in the range of 6-10 km / h, which is related to the vehicle speed when starting with full throttle on a low adhesion road; the vehicle slip rate threshold value is determined by the performance of the vehicle, and the value of the vehicle slip rate threshold value is generally slightly larger than the maximum vehicle slip rate of the vehicle in a non-slip vehicle condition; the speed change rate threshold value is also determined by the performance of the vehicle, and the value of the speed change rate threshold value is generally slightly larger than the maximum speed change rate of the vehicle in a non-slip vehicle condition. The three threshold values are determined by the processing module.

[0053] The application further provides an electronic device, comprising: one or more processors; and a storage device storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement the method described above.

[0054] The application further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor of a computer, the computer executes the method described above.

[0055] The application provides an electric vehicle torque distribution method, system, electronic device and storage medium, and a calculation method of a slip rate is designed, basic information of a vehicle condition is determined according to the slip rate, and torque distribution of front and rear wheels is performed according to the slip rate.

[0056] Therefore, by the electric vehicle torque distribution method of the application, slipping on a low adhesion road can be identified, a slipping working condition is obtained by analyzing a vehicle slip rate, and torque output and four-wheel drive distribution are controlled on this basis, so that the purpose of rapid escape is achieved.

[0057] The above embodiments only exemplarily illustrate the principles and effects of the application, and are not used to limit the application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought of the application should be covered by the claims of the application.

Claims

1. A torque distribution method for an electric vehicle, characterized in that, include: S1: Set the vehicle speed threshold, wheel speed change rate threshold, and vehicle slip rate threshold; S2: Collect vehicle driving data, and calculate the actual wheel speed change rate and the actual vehicle slip ratio based on the vehicle driving data; the vehicle driving data includes vehicle displacement speed and wheel rotation speed, the wheel rotation speed includes front wheel speed and rear wheel speed, the vehicle displacement speed is used as the first reference speed, the smaller of the front wheel speed and the rear wheel speed is used as the second reference speed, the front wheel displacement slip ratio, the front wheel speed slip ratio, the rear wheel displacement slip ratio, and the rear wheel speed slip ratio are obtained based on the vehicle displacement speed and the wheel rotation speed, the maximum value of the front wheel displacement slip ratio and the front wheel speed slip ratio is used as the front wheel slip ratio, and the maximum value of the rear wheel displacement slip ratio and the rear wheel speed slip ratio is used as the rear wheel slip ratio; Wherein, the front wheel displacement slip ratio = |first reference vehicle speed - front wheel speed| / front wheel speed, the front wheel rotation slip ratio = |second reference vehicle speed - front wheel speed| / front wheel speed, the rear wheel displacement slip ratio = |first reference vehicle speed - rear wheel speed| / rear wheel speed, and the rear wheel rotation slip ratio = |second reference vehicle speed - rear wheel speed| / rear wheel speed; S3: Compare the calculated actual wheel speed change rate and actual vehicle slip rate with the wheel speed change rate threshold and vehicle slip rate threshold respectively to determine the vehicle driving condition; S4: Allocate the torque occupancy ratio of the front and rear wheels of the vehicle according to the vehicle's driving conditions and actual slip ratio.

2. The torque distribution method for electric vehicles according to claim 1, characterized in that, In S1, the vehicle speed threshold is taken in the range of 6-10 km / h, which is related to the vehicle speed when a sudden jerk occurs when starting with a large throttle on a low-friction surface; the wheel speed change rate threshold is determined based on the maximum wheel speed change rate of the vehicle in a non-slipping state, and the vehicle slip rate threshold is determined based on the maximum vehicle slip rate of the vehicle in a non-slipping state.

3. The electric vehicle torque distribution method according to claim 2, characterized in that, In S2, the vehicle displacement speed is obtained by a speed measuring instrument located at the bottom of the vehicle, and the wheel rotation speed is calculated by the rotation speed of the corresponding vehicle motor and the wheel radius of the corresponding wheel.

4. The torque distribution method for electric vehicles according to claim 3, characterized in that, In step S2, the formula for calculating the wheel rotation speed is: Wheel rotation speed = Vehicle motor rotation speed Wheel radius 0.377 / ratio, where ratio is the transmission ratio between the corresponding motor and the corresponding wheel of the vehicle.

5. The torque distribution method for electric vehicles according to claim 1, characterized in that, In S2, the front wheel speed is the average of the front left wheel speed and the front right wheel speed of the vehicle, and the rear wheel speed is the average of the rear left wheel speed and the rear right wheel speed of the vehicle.

6. The torque distribution method for electric vehicles according to claim 5, characterized in that, In S2, the actual slip ratio of the vehicle includes the slip ratio of the front wheels and the slip ratio of the rear wheels, and the rate of change of rotational speed is obtained by calculating the rate of change of the wheel rotational speed per unit time.

7. The electric vehicle torque distribution method according to claim 1, characterized in that, In S3, when the vehicle speed is less than the vehicle speed threshold, it is considered a starting condition; when the actual rate of change of wheel rotation speed is greater than the wheel rotation speed change threshold, it is considered a slipping condition; and when the actual slip rate of the vehicle is greater than the vehicle slip rate threshold, it is considered a slipping condition.

8. The torque distribution method for electric vehicles according to claim 7, characterized in that, In step S4, torque is distributed according to the slippage of the front and rear wheels of the vehicle. When the front wheels are slipping, torque is distributed to the rear axle of the vehicle according to the slip ratio of the front wheels; when the rear wheels are slipping, torque is distributed to the front axle of the vehicle according to the slip ratio of the rear wheels.

9. An electric vehicle torque distribution system using any one of claims 1-8, characterized in that, include: The acquisition module collects vehicle driving data, including vehicle displacement speed and wheel rotation speed. The processing module processes the vehicle driving data to obtain the front wheel slip ratio and the rear wheel slip ratio. The vehicle driving data includes vehicle displacement speed and wheel rotation speed. The wheel rotation speed includes front wheel speed and rear wheel speed. The vehicle displacement speed is used as a first reference speed, and the smaller of the front wheel speed and the rear wheel speed is used as a second reference speed. Based on the vehicle displacement speed and the wheel rotation speed, the front wheel displacement slip ratio, the front wheel speed slip ratio, the rear wheel displacement slip ratio, and the rear wheel speed slip ratio are obtained respectively. The maximum value between the front wheel displacement slip ratio and the front wheel speed slip ratio is taken as the front wheel slip ratio, and the maximum value between the rear wheel displacement slip ratio and the rear wheel speed slip ratio is taken as the rear wheel slip ratio; wherein, the front wheel displacement slip ratio = |first reference vehicle speed - front wheel speed| / front wheel speed, the front wheel rotation slip ratio = |second reference vehicle speed - front wheel speed| / front wheel speed, the rear wheel displacement slip ratio = |first reference vehicle speed - rear wheel speed| / rear wheel speed, and the rear wheel rotation slip ratio = |second reference vehicle speed - rear wheel speed| / rear wheel speed; The allocation module compares the front wheel slip ratio and the rear wheel slip ratio with the vehicle slip ratio threshold to determine whether wheel slippage has occurred, and allocates the torque occupancy ratio of the front and rear wheels according to the magnitude of the front wheel slip ratio and the rear wheel slip ratio.

10. The electric vehicle torque distribution system according to claim 9, characterized in that, The front wheel slip ratio in the processing module includes the front wheel displacement slip ratio and the front wheel speed slip ratio, and the rear wheel slip ratio includes the rear wheel slip ratio and the rear wheel speed slip ratio.

11. The electric vehicle torque distribution system according to claim 10, characterized in that, In the allocation module, the vehicle slip rate threshold is determined based on historical data collected by the acquisition module.

12. An electronic device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the electronic device to perform the method as described in any one of claims 1-8.

13. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by the computer's processor, causes the computer to perform the method described in any one of claims 1-8.

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